Blackmagic Forum

Hello guys,

I encounter a problem that drives me crazy. I have a timeline with several clips and for each clip, Davinci reduces the video quality. It's very difficult to colorgrade.

Here a example :




It's a capture of a RED video (8192x4320 - 16 bits). I apply only 2 CST (no correction) :
- RedWideGamutRGB RED Log3G10 to Davinci Wide Gamut Intermediate
- Davinci Wide Gamut Intermediate to REC 709 gamme 2.4 (apply forward OOTF).
- no tone mapping and gamut mapping

I tried every RED input Color space /Gamma and the two Davinci color science (YRGB and YRGB managed).

I tried to delete render cache : no effect.
I don't use proxy media or optimised media.
I tried a lot of options on Preferences or project settings.

I don't understand what happens. I worked on another project in the past without troubles.
I'm on Davinci Resolve 18.6.6.

My config :
AMD RYZEN 7 1700X 8 core
32 GO RAM
GeFOrce RTX 2600 Super 8 Go
Windows 10
My drivers are updated.

Thank for your help.

NB : sorry for my english.

What is your setting here?

No problem with your English, BTW.

I also tried bit Depth with 10 and same thing.

I notice something. When I set my 2 CST, the picture is good but when I add a node and start to modify the exposure for example (works for any type of modification), the quality falls apart.

Don't try to color-correct in the GUI with the Viewer. Read page 2851 of the Resolve 18.6 manual, "Limitations When Grading With the Viewer on a Computer Display." This explains why it's unwise to try to use a computer display for final color correction. The same problem also exists with the "Clean Feed" output, since it's not color managed.

It's fine if you're just learning, but realistically, you need a calibrated monitor and a Decklink or UltraStudio output in order to trust what you're seeing in terms of color and level.

Performance mode in still/stop?

Peter Chamberlain wrote:Performance mode in still/stop?

Performance mode in Stop.

Marc Wielage wrote:Don't try to color-correct in the GUI with the Viewer. Read page 2851 of the Resolve 18.6 manual, "Limitations When Grading With the Viewer on a Computer Display." This explains why it's unwise to try to use a computer display for final color correction. The same problem also exists with the "Clean Feed" output, since it's not color managed.

It's fine if you're just learning, but realistically, you need a calibrated monitor and a Decklink or UltraStudio output in order to trust what you're seeing in terms of color and level.

I understand perfectly but I face off a problem that never happened before.

Disable Performance Mode in Preferences/User/Playback Settings.

Performance mode is disable so it's not that.

Do not forget the scopes are impacted. It's like a double conversion somewhere.

If I don't use CST (i'm in DAVINCI YRGB), picture is fine.

Finally, I found the cause.

It was the render cache. A complete delete resolved everything.

Thanks to all of you. I appreciate your help.